CN1305029C - Systems and methods for improving piezoelectric microactuator operation by preventing unintended microactuator motion disturbances and by preventing microactuator misalignment and damage during manufacturing - Google Patents

Abstract

Systems and methods for improving the operation of piezoelectric microactuators by preventing unintended microactuator motion disturbances and by preventing microactuator misalignment during manufacturing.

Description

Systems and methods for improving piezoelectric microactuator operation by preventing unintended microactuator motion disturbances and by preventing microactuator misalignment and damage during manufacturing

technical field

The present invention relates to magnetic hard disk drives. More specifically, the present invention relates to systems and methods for improving piezoelectric microactuator operation by preventing unintended microactuator movement disturbances and by preventing microactuator misalignment.

Background technique

Currently in the art, different methods are used to increase the recording density of hard disk drives. Figure 1 provides an illustration of a typical drive arm configured to read and write to a magnetic hard drive. Generally speaking, a voice coil motor (VCM) 102 is used to control the movement of a hard drive arm 104 across a magnetic hard drive 106 . Due to the inherent tolerances (dynamic play) in setting the recording head 108 solely by means of the VCM 102, microactuators 110 are currently used to "fine tune" the position of the recording head 108, as described in US Patent No. 6,198,606. The VCM 102 is used for stroke adjustment, while the micro-actuator 110 corrects the position on a small scale to compensate for the tolerances of the VCM 102 (with the arm 104). This allows for smaller recordable track widths, thereby increasing the "tracks per inch" (TPI) of the hard drive (increasing the drive's density).

Figure 2 provides an illustration of the drive arm used in the present technique. For electrical connection with the head 202 , a flexible cable suspension assembly (FSA) 204 with live traces 206 is provided and mounted on the arm 212 . FSA 204 provides an electrical connection between pad 208 near the VCM (not shown) and pad 210 on head 202 .

Mounting the head 202 directly to the FSA 204 as shown presents problems both in head alignment and in the operation of the microactuator, as will be explained below. Furthermore, existing methods of mounting the FSA 204 to the arm 212 also cause problems with ensuring suspension rigidity and correcting the spatial orientation of the recording head, among other problems. Therefore, it would be desirable to have a system and method which, among other advantages, would prevent the problems described above.

Contents of the invention

A system includes an electrical circuit assembly and an actuator frame, the system further comprising:

a spacer element positioned between the circuit assembly and the lower portion of the transmission frame, wherein,

said circuit assembly has a generally O-shaped portion configured such that an upper portion of the transmission frame protrudes through said O-shaped portion; and

The circuit assembly is connected to the spacer element, which in turn is to be connected to the above-mentioned lower part.

A system for a hard disk drive including an actuator frame and a spacer element, the system further comprising:

Circuit assemblies having a generally O-shaped portion in which

The O-shaped portion is configured such that an upper portion of the transmission frame can protrude through the O-shaped portion;

said circuit assembly is attached to said spacer element which in turn is attached to the lower portion of said transmission frame; and

The spacer element is located between the circuit assembly and the lower portion.

A method of producing a system in a hard disk drive, the system including an electrical circuit assembly, an actuator frame, and a spacer element, the method comprising the steps of:

configuring the circuit assembly to have a generally O-shaped portion configured such that an upper portion of the transmission frame protrudes through the O-shaped portion; and

The circuit assembly is connected to the spacer element, and the spacer element is coupled to the lower portion of the transmission frame such that the spacer element is located between the circuit assembly and the lower portion.

Description of drawings

Figure 1 illustrates a typical drive arm configured to read and write to a magnetic hard drive.

Figure 2 illustrates the drive arm used in this technique.

Figure 3 illustrates the drive arm with FSA in accordance with the principles of the present invention.

Figure 4 further illustrates the FSA, shim and drive arm combination of the principles of the present invention.

Figure 5 illustrates a close-up view of the drive arm with the FSA and spacer but without the recording head and piezoelectric transducer mounted, illustrating the principles of the present invention.

Figure 6 illustrates a close-up view of an actuation arm with an FSA and spacer and mounted recording head and piezoelectric transducer illustrating the principles of the present invention.

Detailed ways

Figure 3 illustrates the drive arm with FSA in accordance with the principles of the present invention. In one embodiment, the FSA has an (O-shaped) opening that enables the FSA to mount to the microactuator 304 without interference. In one embodiment, the microactuator 304 includes an actuator frame 306 that supports a head 308 and a piezoelectric member 310 on both sides for adjustment of the position of the head 308 . In order to be able to resist vibrations, a suspension tongue 312 is used, which is mounted on the drive frame 306 by means of an adhesive such as epoxy. In another embodiment, the suspension tongue 312 is mounted to the transmission frame 306 by welding, such as laser welding. Suspension tongue 312 is constrained by a "hammer" or "T" (second hook) 314 at one end and is supported at the other end by a recess 316 .

In one embodiment, a gap 317 between the drive frame 306 and the suspension tongue 312 on the recess 316 of 25 to 50 micrometers (um) is required in order to provide a correct suspension function and to properly align the recording head. Using an FSA 204 similar in construction to that described in FIG. 2 for an actuator similar to that described in FIG. 3 would make it difficult to achieve proper alignment of the recording head. Since head 202 is mounted on FSA 204 and FSA 204 is mounted on arm 212, when head 308 is connected to FSA 302 and FSA 302 is connected to transmission frame 306, force must be applied to the suspension assembly through head 308 and FSA. During bonding with adhesives such as organic epoxies, force must be applied for proper bonding to occur. Since the suspension enables the actuator 306 to move, the forces applied to the head 308 are transferred to the suspension assembly, possibly causing excessive bending and damage to the suspension tongue 312 such that the head 308 is out of alignment (azimuth). Also, when removing the head 308 or FSA 302 (to replace a defective assembly) by applying excessive force to the suspension tongue, damage to the suspension, etc. can also occur. In the case of FSA 204 as shown in Figure 2, the stiffness of FSA 204 can have a great impact on slide rail loading/unloading. FSA stiffness is very large, and thus the loading force of the system needs to be increased.

In one embodiment of the invention, a spacer 318 made of a material such as stainless steel is used and the FSA 302 has an opening for the microactuator 304 . As shown in FIG. 3, spacer 318 is attached to FSA 302 with an adhesive such as epoxy. The FSA 302 is attached to the suspension structure 322 at one end of the drive arm (not shown) with an adhesive such as epoxy, with portions of the FSA 302 being closer to the VCM (not shown) than the microactuator 304 . Due to the rigid spacer 318 attached to the FSA 302 before the FSA is mounted to the suspension structure 322, and due to the fact that the FSA 302 is only glued directly to the transmission frame 306 at the front (away from the VCM), there is no need to apply excessive force directly onto the hanging tongue 312, thereby preventing possible damage/misalignment.

In one embodiment, the microactuator frame is attached to the suspension tongue 312 before the FSA 302 (with spacer 318 ) is attached to the suspension structure 322 . In another embodiment, FSA 302 (with spacer 318 ) is attached to suspension structure 322 before the microactuator frame is attached to suspension tongue 312 .

In one embodiment, head 308 and piezoelectric sensor 305 are attached to microactuator frame 306 before microactuator frame 306 is attached to suspension tongue 312 . In another embodiment, the microactuator frame 306 is attached to the suspension tongue 312 before the head and piezoelectric sensor 305 are attached to the microactuator frame 306 .

As mentioned above, spacer 318 is bonded to FSA 302 , which is then attached to suspension structure 322 . In one embodiment, this is accomplished by installing a spacer 318 (attached to the FSA 302) under the angled tab (first hook) that restricts movement and bonding the FSA to the suspension structure at the rear (towards the VCM) 322, and glue the gasket 318 to the front edge 307 of the transmission frame 306. This avoids applying pressure directly to the suspension tongue 312 .

Figure 4 further illustrates the combination of the FSA, spacer and suspension structure of the principles of the present invention. In one embodiment, the gasket 402 is bonded to the FSA 404 (as shown, to the underside of the FSA 404). FSA 404 and spacer 402 are positioned to hook (limit movement) angled tab 406 at the end of spacer 402 . In one embodiment, the spacer 402 bonded to the FSA 404 is glued to the front 410 of the transmission frame 408 (as shown, glued to the upper side of the transmission frame 408), while the FSA 404 is bonded to the suspension structure (drive arm end) 412. Alignment holes 414 are used to correct the position of shim 402 and FSA 404 on suspension structure 412 .

Figure 5 illustrates a close-up view of a suspension structure 502 with an FSA 504 and a spacer 506 without the recording head and piezoelectric transducer installed in accordance with the principles of the present invention, while Figure 6 illustrates the principles of the present invention with an FSA 604 and a spacer 606 and A close-up view of the suspension structure 602 with the recording head 608 and the piezoelectric sensor 610 mounted.

Although several embodiments have been shown and described in detail herein, it should be recognized that the foregoing covers modifications and variations of the invention which, without departing from the spirit and scope of the invention, belong to scope of the appended claims.

Claims (30)

1. A system comprising an electrical circuit assembly (302) and a transmission frame (306), the system further comprising: a spacer element (318) positioned between the circuit assembly (302) and the lower portion of the transmission frame (306), wherein, said circuit assembly (302) has a generally O-shaped portion configured such that an upper portion of the transmission frame (306) protrudes through said O-shaped portion; and Said circuit assembly (302) is connected to said spacer element (318), which in turn is to be connected to said lower part. 2. The system of claim 1, further comprising: An arm member coupled to said spacer member and said transmission frame. 3. The system of claim 2, wherein said actuator frame is to be coupled with a suspension tongue of said arm member. 4. The system of claim 3, wherein a first hook member engaging a spacer member and a second hook member engaging a suspension tongue limit movement of the transmission frame away from said support arm. 5. The system of claim 1, wherein said actuator frame is a piezoelectric microactuator frame. 6. The system of claim 1, wherein said circuit assembly is a flexible cable suspension assembly. 7. The system of claim 1, wherein said circuit assembly is coupled to said spacer member by an epoxy-resin combination material. 8. The system of claim 1, wherein said circuit assembly is coupled to said lower portion by an epoxy-resin combination material. 9. The system of claim 1, wherein the transmission frame is metal. 10. The system of claim 1, wherein the gasket is stainless steel. 11. A system for a hard disk drive, comprising an actuator frame (306) and a spacer element (318), the system further comprising: A circuit assembly (302) having a generally O-shaped portion wherein The O-shaped portion is configured such that an upper portion of the transmission frame (306) protrudes through the O-shaped portion; said circuit assembly (302) is connected to said spacer element (318) which in turn is to be connected to the lower portion of said actuator frame (306); and The spacer element (318) is positioned between the circuit assembly (302) and the lower portion. 12. The system of claim 11, further comprising: An arm is connected to said spacer member and said transmission frame. 13. The system of claim 12, wherein said actuator frame is connected to a suspension tongue of said arm member. 14. The system of claim 13, wherein a first hook member engaging the shim and a second hook member engaging the suspension tongue limit movement of the actuator frame away from the arm member. 15. The system of claim 11, wherein said actuator frame is a piezoelectric microactuator frame. 16. The system of claim 11, wherein said circuit assembly is a flexible cable suspension assembly. 17. The system of claim 11, wherein said circuit assembly is coupled to said spacer member by an epoxy and resin combination material. 18. The system of claim 11, wherein said circuit assembly is coupled to said lower portion by an epoxy-resin combination material. 19. The system of claim 11, wherein the transmission frame is metal. 20. The system of claim 11, wherein the gasket is stainless steel. 21. A method of producing a system in a hard disk drive comprising an electrical circuit assembly, an actuator frame and a spacer element, said method comprising the steps of: configuring the circuit assembly to have a generally O-shaped portion configured such that an upper portion of the transmission frame protrudes through the O-shaped portion; and The circuit assembly is connected to the spacer element, and the spacer element is coupled to the lower portion of the transmission frame such that the spacer element is located between the circuit assembly and the lower portion. 22. The method of claim 21, further comprising: A support arm is coupled to the spacer element and the transmission frame. 23. The method of claim 22, wherein the actuator frame is coupled to a suspension tongue of the arm member. 24. The method of claim 23, wherein a first hook member engaging the spacer and a second hook member engaging the suspension tongue limit movement of the transmission frame away from the arm member. 25. The method of claim 21, wherein the actuator frame is a frame of a piezoelectric microactuator. 26. The method of claim 21, wherein the circuit assembly is a flexible cable suspension assembly. 27. The method of claim 21, wherein said circuit assembly is coupled to said spacer member by an epoxy-resin combination material. 28. The method of claim 21, wherein said circuit assembly is coupled to said lower portion by an epoxy-resin combination material. 29. The method of claim 21, wherein said transmission frame is metal. 30. The method of claim 21, wherein said shim is stainless steel.

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